using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Data.OracleClient;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Web;
using System.Xml;
using Amib.Threading;
using CCSTrace.CCS.Domain;
using CCSTrace.CCS.Object;
using Iesi.Collections.Generic;
using NLog;

namespace CCSTrace.CCS
{
    public class CcsMain
    {
        private const string DbConfigFilename = "DBConfig.xml";

        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
        private static CcsMain _instance;

        private readonly int _connectionCount = 1;
        private OracleConnection _mainConn = null;

        private SmartThreadPool _mainjobThreadPool = null;
        private readonly object _syncDbQueue = new object();
        private readonly Queue<OracleConnection> _dbQueue = new Queue<OracleConnection>();
        private readonly List<string> _processingCases = new List<string>();
        private readonly List<KeyValuePair<string, int>> _waitingCases = new List<KeyValuePair<string, int>>();//Record the case when the case's FDR processed by another


        public CcsMain()
        {
            _mainjobThreadPool = new SmartThreadPool();
            // Startup();
        }

        public string AppDataPath { get; set; }

        public SortedSet<int> ProcessingFdr { get; } = new SortedSet<int>();

        public static CcsMain Instance => _instance ?? (_instance = new CcsMain());

        public List<string> ProcessingCases => _processingCases;

        public List<KeyValuePair<string, int>> WaitingCases => _waitingCases;

        public void Startup()
        {
            Logger.Info("CCSMain Startup.");

            try
            {
                ReadXml();
                Logger.Info("CCSMain ReadXml Complete.");

                if (_mainConn == null)
                    _mainConn = CreateConnection();
                Logger.Info("CCSMain has been connected database.");

                GlobalVariable.CcsCodelist = new CcsCodelist(_mainConn);
                GlobalVariable.EosCodelist = new EosCodelist(_mainConn);

                for (var i = 0; i < _connectionCount; i++)
                {
                    lock (_syncDbQueue) _dbQueue.Enqueue(CreateConnection());
                }
            }
            catch (Exception e)
            {
                Logger.Error(e, e.Message);
                throw;
            }

            var addrContrast = AddrContrast.Instance;
            addrContrast.initialize(_mainConn);

            CCSEventRecord ccsEventRecord = GetWaitRecord(_mainConn);

            if (ccsEventRecord != null)
            {
                OracleConnection conn;
                lock (_syncDbQueue) conn = _dbQueue.Dequeue();
                ProcessCase(ccsEventRecord, conn);
            }

            STPStartInfo stpStartInfo = new STPStartInfo
            {
                IdleTimeout = GlobalVariable.IdleTimeout*1000,
                MaxWorkerThreads = GlobalVariable.MaxThreadSize,
                MinWorkerThreads = GlobalVariable.MinThreadSize
            };
            _mainjobThreadPool = new SmartThreadPool(stpStartInfo);
            Logger.Info("Create Thread Pool.");
        }

        public void Shutdown()
        {
            _mainjobThreadPool.Shutdown(true, 1000);
            _mainjobThreadPool.Dispose();
            _mainjobThreadPool = null;
            GC.Collect();
            GC.WaitForPendingFinalizers();
        }

        public void AcceptEvent(CCSEventRecord ccsEventRecord)
        {
            /*
            WorkItemCallback workItemCallback = new WorkItemCallback(this.DoWork);
            _mainjobThreadPool.QueueWorkItem(workItemCallback, ccsEventRecord);
            WIGStartInfo wigStartInfo = new WIGStartInfo()
            {
                FillStateWithArgs = true,
            };
            _wig1 = _smartThreadPool.CreateWorkItemsGroup((int)spinCon1.Value, wigStartInfo);
            _wig2 = _smartThreadPool.CreateWorkItemsGroup((int)spinCon2.Value, wigStartInfo);

            */

            int i = 0;
            int reConnectCount = 1;

            while (i <= reConnectCount)
            {
                try
                {
                    if (InsertCCSEventRecord(ccsEventRecord, _mainConn))
                    {
                        if (_dbQueue.Count > 0)
                        {
                            //將EVETNQUERY的案件狀態改為開始處理
                            CCSEventRecord waitCcsEventRecord = GetWaitRecord(_mainConn);

                            if (waitCcsEventRecord != null)
                            {
                                OracleConnection conn = null;
                                lock (_syncDbQueue) conn = _dbQueue.Dequeue();
                                ProcessCase(waitCcsEventRecord, conn);
                            }
                        }

                        break;
                    }
                }
                catch (Exception e)
                {
                    Logger.Error(e, e.Message);
                    if (_mainConn.State == ConnectionState.Closed)
                    {
                        i++;
                        if (i > reConnectCount)
                            throw;
                    }
                    else
                        throw;
                }
            }
        }

        private void ReadXml()
        {
            XmlReader reader = null;

            try
            {
                string file = Path.Combine(AppDataPath, DbConfigFilename);
                // 建立 XML 讀取器
                XmlReaderSettings settings = new XmlReaderSettings();
                settings.IgnoreComments = true; // 不處理註解
                settings.IgnoreWhitespace = true; // 跳過空白
                settings.ValidationType = ValidationType.None; // 不驗證任何資料
                reader = XmlReader.Create(file, settings);

                // 進入讀取主要部分
                while (reader.Read())
                {
                    switch (reader.NodeType)
                    {
                        case XmlNodeType.Element:
                            string localName = reader.LocalName; // 取得標籤名稱

                            // Step 3: 讀取 FileInfo 標籤的屬性
                            if (localName.Equals("DBSetting"))
                            {
                                GlobalVariable.ConnectionString =
                                    $"Data source={reader["DataSource"]};User Id={reader["UserId"]};Password={reader["Password"]};";
                                GlobalVariable.TraceConnectionString =
                                    $"{reader["UserId"]}/{reader["Password"]}@{reader["DataSource"]}";
                                string token = reader["ConnectionCount"];
                                if (token != null)
                                {
                                    GlobalVariable.MaxConnectionCount = int.Parse(token);
                                }
                                token = reader["ShowError"];
                                if (token != null)
                                {
                                    GlobalVariable.ShowError = bool.Parse(token);
                                }
                            } else if (localName.Equals("ThreadSetting"))
                            {
                                string token = reader["maxThreadSize"];
                                if (token != null)
                                {
                                    GlobalVariable.MaxThreadSize = int.Parse(token);
                                }
                                token = reader["minThreadSize"];
                                if (token != null)
                                {
                                    GlobalVariable.MinThreadSize = int.Parse(token);
                                }
                            }

                            break;
                    }
                }
                reader.Close();
            }
            catch (XmlException xe)
            {
                Logger.Error(xe, xe.Message);
                reader?.Close();
            }
        }

        private OracleConnection CreateConnection()
        {
            OracleConnectionStringBuilder builder = new OracleConnectionStringBuilder(GlobalVariable.ConnectionString)
            {
                MaxPoolSize = 20,
                MinPoolSize = 5,
                Pooling = true
            };
            string connectstring = builder.ToString();

            OracleConnection dbConn = new OracleConnection(connectstring);

            dbConn.Open();

            return dbConn;
        }

        [MethodImpl(MethodImplOptions.Synchronized)]
        private bool InsertCCSEventRecord(CCSEventRecord ccsEventRecord, OracleConnection conn)
        {
            OracleTransaction transaction = null;

            try
            {
                if (conn.State == ConnectionState.Closed)
                    conn.Open();

                transaction = conn.BeginTransaction();

                if (ccsEventRecord.InsertDb(conn, transaction))
                {
                    var ccsEventQuery = new CCSEventQuery
                    {
                        CcsId = ccsEventRecord.CcsId,
                        Meter = ccsEventRecord.Meter,
                        CaseStatus = (int) CCSCaseState.EventInitial,
                        ChangeTime = ccsEventRecord.AcceptTime
                    };


                    if (ccsEventQuery.Insert(conn, transaction))
                        transaction.Commit();
                    else
                    {
                        if (transaction.Connection.State == ConnectionState.Open)
                            transaction.Rollback();

                        throw new Exception("案件未受理成功。");
                    }
                }
                else
                {
                    if (transaction.Connection.State == ConnectionState.Open)
                        transaction.Rollback();

                    throw new Exception("案件未受理成功。");
                }
            }
            catch (OracleException e)
            {
                Logger.Error(e, e.Message);

                if (transaction != null && (transaction.Connection.State == ConnectionState.Open))
                    transaction.Rollback();

                throw;
            }
            catch (Exception ex)
            {
                Logger.Error(ex, ex.Message);

                if (transaction != null && (transaction.Connection.State == ConnectionState.Open))
                    transaction.Rollback();

                throw;
            }

            return true;
        }

        private delegate void WorkerThreadHandler();

        private void ProcessCase(CCSEventRecord ccsEventRecord, OracleConnection conn)
        {
            try
            {
                if (conn.State == ConnectionState.Closed)
                    conn.Open();

                ProcessEvent processEvent = new ProcessEvent(ccsEventRecord, conn, GlobalVariable.TraceConnectionString);
                processEvent.ThreadFinish += ThreadEndEventProcess;

                ThreadStart threadStart = processEvent.Run;
                Thread thread = new Thread(threadStart);
                thread.Start();
            }
            catch
            {
                lock (_syncDbQueue) _dbQueue.Enqueue(conn);
            }
        }

        private void ThreadEndEventProcess(object sender, ThreadEndEvent e)
        {
            //將EVETNQUERY的案件狀態改為開始處理
            CCSEventRecord waitCcsEventRecord = GetWaitRecord(e.GetConnection());

            try
            {
                if (waitCcsEventRecord != null)
                    ProcessCase(waitCcsEventRecord, e.GetConnection());
            }
            finally 
            {
                lock (_syncDbQueue) _dbQueue.Enqueue(e.GetConnection());
            }
        }

        [MethodImpl(MethodImplOptions.Synchronized)]
        private CCSEventRecord GetWaitRecord(OracleConnection conn)
        {
            string processCcsid = "";
            string ccsid = "";
            CCSEventRecord ccsEventRecord = null;

            foreach (var obj in _waitingCases)
            {
                var ccsId = obj.Key;
                var fdrid = obj.Value;

                if (ProcessingFdr.Contains(fdrid)) //該條饋線仍有案件在處理中
                    processCcsid = processCcsid + "'" + ccsid + "',";
                else
                {
                    ccsid = ccsId;
                    _waitingCases.Remove(obj);
                    break;
                }
            }

            if (ccsid.Length == 0)  //沒有因同饋線而在等候中的案件
            {
                var sqlStmt = "SELECT Q.CCSID AS CCSID FROM CCS.EVENTQUERY Q,CCS.EVENTRECORD R WHERE Q.CASESTATUS IN (" + 
                    (int) CCSCaseState.EventInitial + "," + 
                    (int) CCSCaseState.EventProcess + ")";

                processCcsid = _processingCases.Aggregate(processCcsid, (current, item) => current + "'" + item + "',");

                if (processCcsid.Length != 0)
                    sqlStmt = sqlStmt + " AND Q.CCSID NOT IN (" + processCcsid.Substring(0, processCcsid.Length - 1) + ")";

                sqlStmt = sqlStmt + " AND Q.CCSID = R.CCSID AND ROWNUM < 2 ORDER BY Q.CHANGETIME";
                OracleCommand command = new OracleCommand(sqlStmt, conn);
                OracleDataReader reader = command.ExecuteReader();

                try
                {
                    if (reader.Read())
                        ccsid = reader["CCSID"].ToString();
                }
                catch (Exception e)
                {
                    Logger.Error(e, e.Message);
                }
                finally
                {
                    reader.Close();
                    command.Dispose();
                }
            }

            if (ccsid.Length != 0)
                ccsEventRecord = new CCSEventRecord(ccsid, conn);

            if (ccsEventRecord != null)
            {
                CCSEventQuery ccsEventQuery = new CCSEventQuery
                {
                    CcsId = ccsEventRecord.CcsId,
                    CaseStatus = (int) CCSCaseState.EventProcess
                };
                //先將EVETNQUERY的案件狀態改為開始處理

                OracleTransaction transaction = conn.BeginTransaction();

                try
                {
                    if (ccsEventQuery.UpdateCaseStatus(conn, transaction))
                    {
                        Logger.Info("更新EVENTQUERY的案件狀態為處理中.(CCSID = " + ccsEventRecord.CcsId + ")");
                        transaction.Commit();
                        _processingCases.Add(ccsEventRecord.CcsId);
                    }
                    else
                    {
                        Logger.Error("無法更新EVENTQUERY的案件狀態.(CCSID = " + ccsEventRecord.CcsId + ")");

                        if (transaction.Connection.State == ConnectionState.Open)
                            transaction.Rollback();
                    }
                }
                catch (Exception e)
                {
                    if (transaction.Connection.State == ConnectionState.Open)
                        transaction.Rollback();

                    Logger.Error(e, e.Message);
                    ccsEventRecord = null;
                }
            }

            return ccsEventRecord;
        }
    }
}